1. Field of the Present Invention
The present invention relates to a detecting apparatus for AC motor malfunction and a distribution panel having the same, and more specifically, to a detecting apparatus for AC motor malfunction and a distribution panel having the same capable of detecting an abnormal state by using a current delay property of an AC motor and outputting a malfunction signal to an alarming device, a shutdown device or a recording device etc.
2. Description of the Related Art
Generally, where it has a failure in an AC motor, an alarm is sounded or an operation of the motor is cut off. Also, it inspects the overload of the motor through the measurement of the current and the motor is stopped in case of overload current so as to protect it from the overload. However, since this overcurrent detection mode is an alternative to the fault current, it is insufficient to previously protect the motor.
Defect inspection of insulation layer of a motor coil is conducted by measuring an insulation resistance or a visual inspection of the skilled expert, after it stops the motor. However, it is difficult to find out a weak layer insulation failure such as a short circuit of coils etc. through the insulation resistance measurement method or the visual detection.
Korea published patent KR10-2012-0100280A discloses a single AC motor controller for detecting a malfunction of a single phase AC motor based on the counter electromotive force. In the prior art, it detects the counter electromotive force, outputs pulse signals in proportion to the counter electromotive force at a predetermined distance of time, and determines the malfunction of the motor based on two pulse signals. However, in the detection of the motor malfunction using the counter electromotive force, the reverse rotation of the motor or the lifetime of the phase capacitor can be only detected. That is, it is difficult to determine overheat, overcurrent, and layer insulation failure etc. of the motor.